Production of textile materials



Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE PRODUCTION OF TEXTILE MATERIALS tion of Delaware No Drawing. Application October 22, 1938, Se-

rial No. 236,576. In Great Britain November 2 Claims.

the saponification of textile materials made of cellulose acetate or other organic esters of cellulose. While all these celluosic materials have an afiinity for cotton dyestuffs, the degree of afllnity of one type of material may differ from that of another type of material, and indeed the degree of aflinity of the same type of material may vary according to the processes to which it has been subjected. Thus, for example, the degree of aflinity of mercerised cotton may be different from that of unmercerised cotton, and that of artificial cellulosic materials obtained by the saponification of ordinary dry spun cellulose acetate yarn may be different from that of such materials obtained by the saponiiication of stretched cellulose acetate yarn.

In consequence of the different aflinities of the various types of cellulosic materials, difliculty may arise when it is desired to colour articles containing two or more types of cellulosic materials in a solid shade as, for example, in the dyeing of hose, in which the tops and feet are frequently of cotton and the legs of regenerated cellulose yarn.

It has now been discovered that the dyeing difliculties referred to above may be avoided by subjecting the materials having the greater affinity for cotton dyestuffs to an esterification or etherification process, so as to introduce a small proportion of organic radicle into the materials. In general, when only two types of cellulosic materials are to be employed in the production of an article it is necessary to esterify or etherify only the constituent which has the greater affinity for the cotton dyestufl. Thus, for example, in general cotton has a greater aifinity for cotton dyestuffs than has regenerated cellulose yarn obtained by the saponification of stretched cellulose acetate yarn, and in such a case the cotton yarn is slightly esterified or etherified. 0n the other hand, regenerated cellulose yarn obtained by the viscose and cuprammonium processes usually has more afllnity for cotton dyestufis than has cotton yarn, so that when these types of materials are to be combined in the production of an article it is the regenerated cellulose yarn which is esterified or etherified. The exact degree of esterification or etherification of course depends upon the particular circumstances, especially upon the two types of materials which are to be combined, but in general the degree of esterification or etherification necessary corresponds to a weight increase of 5% or less, particularly about 1.5 to 2.5%.

The invention includes the process of modifying the aflinity of cellulosic yarn, the production of fabrics and other materials containing purely cellulosic yarns and the modified yarns, and the process of colouring the,fabrics and other ma-' terials in solid. shades with cotton dyestuffs,

The most suitable agent for treatment of the materials is acetic anhydride, though otheresterifying agents, for example acetyl chloride, propionic and butyric anhydrides and other lower fatty acid derivatives, 1. e. of an acid containing not more than six carbon atoms may, if desired,

be employed. Etherifying agents, e. g. ethylwhich are ferric, stannic and zinc chlorides, pref erably used in conjunction with hydrochloric acid or a small proportion of acid chloride. Acid catalysts such as sulphuric acid or perchloric acid may be used, but they are in general less suitable, and if employed should be used at low temperatures and in a low concentration. It acid chlorides or alkyl halides or sulphates are employed, preferably a small proportion of basic substance, which may be organic or inorganic, is present to neutralise the acid formed during the reaction.

The following is an example of the treatment of cotton according to the process of the present invention in order to reduce slightly its aflinity for cotton dyestuffs:

' Cotton yarn in hank form is first boiled for about 4-6 hours in a 1% solution of caustic soda at a temperature of to C. and washed off well. It is then treated for 20 to 30 minutes at about 30 C. in a 1% solution of sodium hypochlorite. The are then drained, treated Parts Carbon tetrachloride 57.5 Acetic anhydri 30 Acetic acid 11.5 Acetyl chlor 1 Zinc chloride 1 After completion of the treatment the yarn is removed from the bath, washed ofi with carbon tetrachloride and air-dried. Finally, it is washed off in 5% acetic acid followed by a weak ammonia bath and dried.

The inventionincludes all kinds of mixed textile materials containing purely cellulosic yarns and the modified yarns. Thus, for example, the two types of yarns may be present in doubled yarns or in ,a woven, knitted or netted fabric. In the case of woven fabrics the weft may consist wholly of one type of yarn and the warp wholly of the other type of yarn or both types of yarn maybe in the weft and/or in the warp.

The mixed textile materials may be dyed with any suitable cotton dyestuffs but it will be understood that the particular dyestufi employed will depend to some extent on the proportion and 1 nature of the organic substituent radicle present in the modified textile material. Examples of dyestufls which may be employed are Chrysamine G (Colour Index No. 410), Chlorazol'Black LF (Colour Index No. 582), and the following dyestuffs described in Farbstofitabellen by Gustav Schultz, 1932, vol. 2, 7th edition, on the pages given in parenthesis following their names: Chlorazol Brown PB (p. 50), Diamine Brilliant Scar let S (p. 68), Diamine Fast Blue FFG (p. 69) and Diamine Green HS (p.70). I

. Having described our invention what we desire to secure by Letters Patent is:

1. Process for the production from at least two types of cellulosic yarns having different a'flinities for cotton dyestuffs of textile products-capable of being dyed a solid shade with said dyestuffs, which comprises introducing into the yarns having the greater affinity for said dyestufis acetyl radicles in a proportion corresponding with a weight increase of "from 1.5 to 2.5% whereby their aflinity is reduced to that of the yarns having the lowest aflinity and then forming the products from the modified and unmodified'yarns.

2. Textile products capable of being dyed a solid shade with a cotton dyestufl and containing a purely cellulosic yarn and at least one type of modified cellulosic yarn containing an acetyl radicle in a proportion corresponding with a weight increase of from 1.5 to 2.5% whereby the modified yarn has a degree of aflinity for cotton dyestufls equal to that possessed by the purely. cellulosic yarn.

GEORGE HOLLAND ELLIS. ROBERT WIGHTON MONCRIEFF. 

